1. Field of the Invention
The present invention relates generally to the field of telephony. More specifically, the present invention discloses a test system that enables the automated testing of line termination systems when they are replaced with newer or more capable technology.
2. Statement of the Problem
In the applications considered herein, line termination systems interface on the network side with the traditional copper twisted pair telephone line which provides telephone service to subscribers at the other terminus. These line termination systems may take the form of conventional central office line frames associated with the local switching system or may be “access systems” which reside in a remote location such as a field cabinet. In any case, when an existing line termination system that is providing service to subscribers is to be replaced with a different line termination system, it is imperative that the designation of subscriber pairs on the new system and those of the existing system be consistent for the conversion from the first system to the second to be seamless. For example, a subscriber pair that is known to the existing line termination system as a given Directory Number (DN) must be physically associated with a pair in the replacement line termination system that corresponds to that same DN for service to be uninterrupted upon transfer to the replacement system. In the prior art, insuring the proper association of the new and existing line termination system pairs either relies on proprietary functionality within the replacement switching system or entails laborious manual testing and verification. The instant invention discloses a method and system for testing the accuracy of installation of replacement line termination systems independently of equipment vendors and technology in a manual or fully automated manner.
Wireline telephone service providers use line termination systems to interconnect between a subscriber's conventional telephone station equipment and the greater telephone network generally through a local switching system. Commonly these line termination systems take the form of proprietary line frames which are integrated into, and a part of, the local switching system. When technological advances, obsolescence, or other factors necessitate the conversion from the existing line termination system to another one, the correct association of subscriber pairs between the two systems presents an installation challenge. The conversions from older electromechanical switching systems to newer electronic switching systems that took place generally between the years 1980 and 2000 in North America exemplify this problem. It was customary to connect the subscriber pairs terminating on the older switching system simultaneously to those of the replacement system's subscriber pairs. The line termination systems on the replacement systems were designed so as not to interfere with the installed system's operation nor provide service to these subscribers until such time as testing is complete and all subscribers can be simultaneously transferred to the new system, a procedure known as a “flash cutover”.
These conversions of local switching systems frequently involve many thousands of subscriber pairs and to facilitate the test process automation is highly desirable. Modern switch vendors have incorporated this functionality in their proprietary line termination systems (line frames) in association with the proprietary control and test facilities which constitute the switching system. For example, in the commonly deployed Alcatel-Lucent 5ESS®, this capability is referred to as “Office To Office” (OTO) testing. When a 5ESS is installed to replace an existing switch, OTO testing employs the internal “test trunk” assets of the existing switch and that of the replacement 5ESS to verify that the physical subscriber pairs that the existing switch associates with a given directory number are identical to that of the replacement switch.
As the currently deployed central office technology is now itself becoming obsolete, telephone companies are replacing traditional local switching systems with general purpose line termination systems, such as access systems, which do not have these internal testing capabilities and do not accommodate these proprietary installation verification methodologies. Herein lies a problem in the art.